Dr. Ahmad Redaa
2024-10-14
Source: https://openpress.usask.ca
Source: https://openpress.usask.ca
Source: https://openpress.usask.ca
Source: https://openpress.usask.ca
Source: https://openpress.usask.ca
Source: https://openpress.usask.ca
Source: https://openpress.usask.ca
Each category in this classifications represents a specific chemical and mineralogical composition of the protolith
Six primary classes:
| Classification | Protolith | Composition | Common Minerals | Examples (Before) | Examples (After) |
|---|---|---|---|---|---|
| Pelites | Mudstone, shale | High aluminum | Mica, garnet, kyanite | Shale, mudstone | Slate, schist, gneiss |
| Psammites | Sandstone | High silica (quartz, feldspar) | Quartz, feldspar | Sandstone | Quartzite, meta-sandstone |
| Calcareous Rocks | Limestone, dolostone | High calcium carbonate | Calcite, dolomite, diopside | Limestone, dolostone | Marble, calc-silicate rock |
| Quartzo-Feldspathic Rocks | Granite, arkosic sandstone | High quartz and feldspar | Quartz, feldspar | Granite, arkose | Gneiss, granulite |
| Mafic Rocks | Basalt, gabbro | Moderate silica, high Fe, Mg | Amphibole, pyroxene, plagioclase | Basalt, gabbro | Amphibolite, granulite |
| Ultramafic Rocks | Peridotite | Very low silica, high Mg, Fe | Olivine, serpentine, talc | Peridotite |